Effects of ammonia on intestinal microflora and productive performance of laying ducks.

Atmospheric ammonia is harmful to poultry and human health. The effect of ammonia on the intestinal microflora of laying ducks is still unknown. In this study, the effects of atmospheric ammonia and exposure time on the intestinal microflora of laying ducks were investigated using 16S rDNA sequencing technology. The body weight, ovary weight, spleen weight, liver weight, and productive performance of laying ducks were also recorded, and the relationship between intestinal microflora diversity and productive performance was analyzed. The results showed that Bacteroidetes, Firmicutes, and Proteobacteria were the dominant bacterial phyla. At the phylum and genus levels, with the exception of the phylum Firmicutes and the genus Sutterella, the top 10 most abundant phyla and genera differed significantly when the ammonia concentration was increased from 10 to 75 ppm and/or the exposure time was extended from 10 to 30 D. Laying rate was highly significantly lower in ducks exposed to 75 ppm ammonia for 10 D compared with those exposed to 10 ppm ammonia for 10 D. Body, ovary, and spleen weights also decreased when the ammonia concentration was increased. At the genus level, Flavonifractor was highly significantly positively correlated with ovary weight. Methanocorpusculum and Anaerotruncus were significantly positively correlated with ovary weight. Lactobacillus was significantly positively correlated with spleen weight. Phascolarctobacterium, Sphaerochaeta, Erysipelotrichaceae_UCG.004, and Lactococcus were significantly positively correlated with spleen weight. These results indicated that ammonia affected the diversity of the intestinal microbiota and the productive performance of laying ducks. Several intestinal microbiota genera were also correlated with organ weights.